Hydatid disease in central Utah has its own unique epidemiology, and relates to a close family involvement with the sheep industry, indiscriminant discarding of sheep carcasses, lack of leash laws, lack of separation between rural and urban living in small communities, and a heretofore general unawareness of the seriousness and mode of transmission of this disease. Since a marked decline in the present of infected dogs is now apparent after our 6-year effort, we believe that continued implementation of the recommended preventive and control measures is needed. As soon as each measure proves successful in central Utah, we propose to extend this to neighboring states and particularly to the Indian reservations in an attempt to aid individuals living in those regions where recent cases of hydatid disease have occurred. Much of our proposed program will be centered around the continued production and distribution of educational aids and assistance with public health clinics in endemic sites. Since some ranchers have dogs which prove to be infected each year, the results of a proposed attitudinal questionnaire will hopefully determine which factors need to be corrected in order to achieve maximum support for the program. We also intend to test selected chemotherapeutic agents against both the adult and larval forms of the parasite, study the impact of additional environmental factors on the protoscolices and egg stages, and attempt the development of suitable immuno-diagnostic procedures to detect those sheep in endemic regions which harbor hydatid cysts.